The invention concerns a wet/dry vacuum cleaner and in particular a shoe attachment for the intake of a vacuum cleaner which is suitable for picking up dry materials, wet materials and even liquids. The invention is particularly useful for the intake of an electric vacuum cleaner, such as that shown in U.S. application Ser. No. 134,776 filed Mar. 28, 1980, entitled "COMPACT WET-DRY ELECTRIC VACUUM CLEANER", and assigned to the assignee hereof now U.S. Pat. No. 4,334,337, issued June 15, 1982.
An electric vacuum cleaner generally includes suction generating apparatus, such as a suction fan, which communicates with an intake orifice. To increase suction force at the intake orifice, the orifice is typically of reduced width across at least one dimension and the reduced size of the orifice increases the speed of air flow through the orifice.
An electric vacuum cleaner may be of the type where the intake is at the front or the underside of a housing that rides along the surface to be suctioned cleaned, or it may be of the type having an inlet hose with the intake orifice in the nozzle at the end of the hose. The present invention is particularly useful in conjunction with the first type of vacuum cleaner, although it is useful with any type of vacuum cleaner nozzle.
Furthermore, some vacuum cleaners are known as wet/dry types, in that they are adapted to suck in dry particulate materials, wet or damp materials and even liquids. The vacuum cleaner of the above-mentioned patent application is just such a vacuum cleaner. Dry particulate materials are lighter in weight and thus can be sucked in using a smaller suction force. But wet materials and liquids in particular require a relatively greater suction force to be sucked in. In some circumstances, a vacuum cleaner with an intake suction force only great enough to take in dry particulate materials may not have adequate suction force for taking in wet particulate materials or liquids.